肉包铁

肉包铁出去都一定要小心

You must be very careful when going out on a two-wheeler.

现在自行车速度不是一般的快,自行车肉包铁很危险

Bicycles are unusually fast nowadays; riding a bicycle is very dangerous.

开车是铁包肉，你骑车是肉包铁,安全意识都没有,真的是不要命

Driving represents iron wrapping flesh, but you are riding flesh wrapping iron. You have no safety awareness, truly risking your life.